721169 has 2 divisors, whose sum is σ = 721170. Its totient is φ = 721168.

The previous prime is 721163. The next prime is 721177. The reversal of 721169 is 961127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 483025 + 238144 = 695^2 + 488^2 .

It is a cyclic number.

It is not a de Polignac number, because 721169 - 2⁸ = 720913 is a prime.

It is a super-2 number, since 2×721169² = 1040169453122, which contains 22 as substring.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (721163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360584 + 360585.

It is an arithmetic number, because the mean of its divisors is an integer number (360585).

2⁷²¹¹⁶⁹ is an apocalyptic number.

It is an amenable number.

721169 is a deficient number, since it is larger than the sum of its proper divisors (1).

721169 is an equidigital number, since it uses as much as digits as its factorization.

721169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 756, while the sum is 26.

The square root of 721169 is about 849.2166979046. The cubic root of 721169 is about 89.6765757595.

The spelling of 721169 in words is "seven hundred twenty-one thousand, one hundred sixty-nine".